Hackable Geiger Counter

[Aaron] A.K.A. [A1ronzo] at SparkFun has put together a hackable USB Geiger Counter. In his tutorial, he gets the Geiger counter to work as a random number generator. Later, he analyzes and discusses how well it works as a random number generator. In the past, we have seen a number of radiation detectors hacks such as the Mr. Fission digital Geiger counter, a count accumulator, and a Polonium detecting pen, Besides our inital thoughts of speeding up the number generation, and using it as a special character device, what else can you come up with to do with this device?

If you want random numbers, just use a resistor, an op-amp, and an ADC. Resistor noise is thermal noise and is just as random as radiation. You may have to do a bit of trickery to avoid any bias generated by the ADC, but at the rate the data will be coming in you can afford to combine several samples together to get each bit.

The best use for this radiation detector is probably as a data logger, perhaps used alongside a GPS to record hot spots. Too bad it doesn’t have a built in clock.

This is a nice design, even with the high voltages! I’ve built solid state particle detectors that work under 18 volts, but in my experience they are rather picky about noise and need Faraday cages… they are a fair bit faster though.

My first thoughts were: Wow, they didn’t use a wrong algorithm to produce numbers from sampled entropy. It would be pretty hard to maliciously inject nonrandomness into this system.

I may have used a Schmitt trigger to clean up the signal instead of (or in addition to) a filter, but I can’t argue with their results!

Most gas discharge tubes will function as radiation detectors with a bit of hacking to keep light out. I’ve used the humble NE-2, expect that VR tubes would work, and have seen racks of standard long fluro’s detecting cosmic rays.

A way of generating low speed noise is to make up a cotton-wool & damp salt cell.

you couldn’t replace a dosimeter with this for a number of reasons, number one the film badges have to be permanently readable, and even if you added a datalogger to this you couldn’t power it forever, second with only one of those lnd712 tubes, you couldn’t read anything dangerous, even with the recommended 6 to 10 tubes in parallel you couldn’t read over a tenth of a rad…about the only geiger related thing this is good for is finding random radioactive painted dishes and antiques, which there are a surprisingly lot of.

Well if it really costs 150 it isn’t worth the effort. I can get a REAL one for that much. Yayy!!!! UnitedNuclear.com moved very close to me recently. Its my favorite site and its like a tiny candy store with bunches of variety. Everyone should check it out. If that doesn’t get you to this is their slogan:

Make a hand held one that is sensitive enough, add a GPS locator with GSM automatic alert signaling, then give one to every boy scout group, sell or rent it to excursionists, etc. Voila: you get instant radioactive-mapping which will help a lot to bust illegal nuclear waste disposal.

Memory chips make great radiation detectors, lower the refresh rate and hammer them with read write cycles, the error rate is directly proportional to radiation level. This technique was used in the 1960’s and was used aboard skylab as a cosmic ray detector. ..

There would be inherent biases in that arrangement. By nature, the individual counters (even the individual tubes) would be more or less sensitive, so in your arrangement some digits would be more or less common.

Did anybody check how to upgrade the firmware via USB connector ? It’s not a good idea to send 0’s and 1’s per event. It should sent cps or cpm (counts per second or minute). Has anybody a idea of an ATMEL programming device to connect to it ?